The present invention relates to a heat-sensitive recording material utilizing the color reaction between a colorless or light-colored basic dye and a developing agent and relates to a heat-sensitive recording material which is excellent in the retainability of recorded images and water-resistance of recording layer and low in adhesion of smudges.
Heat-sensitive recording materials have been well known in which the color reaction between a colorless or light-colored basic dye and an organic or inorganic developing agent is utilized and both of the colorforming materials are contacted each other to produce a recorded image. Such a heat-sensitive recording material is relatively low in price and the recording equipments used for it is compact and easy in maintainance. Therefore, it has been used in a wide field not only as a recording medium for facsimiles and various computers.
For example, as one of the fields of application, the heat-sensitive recording label for POS (point of sales) system of retail stores and the like can be exemplified. However, as the system has been popularized, their prolonged uses attached on commercial products have increased aside from the food labels which discharge the role in a short period as before. However, in such applications, they contact with water, laps, oils and the like and the recorded images are discolored or the recording layer is peeled off to deteriorate remarkably the product image as the result. Therefore, it is required that a heat-sensitive recording material has the retainabilities such as water resistance, plastisizer resistance, oil resistance and the like.
Also, a heat-resistant recording material is required which can record in a heat-resistant facsimiles at a speed of 10 seconds or lower for A4 size and in a heat-sensitive printer at a speed not lower than 120 letters/second. However, when the recording speed is increased, smudges adhered on the head during recording give no uniform recorded image disadvantageously.
Though a method for adding a paraffin wax to the recording layer for eliminating head smudges had been described in JP A 1-133783, it gave no sufficient water-resistance by the effect of the emulsifiers and the like used for finely dispersing the paraffin wax.
An object of the present invention is to provide a heat-sensitive recording material which is excellent in the retainability of recorded images and water-resistance of recording layer and low in adhesion of head smudges.